Cross-over switch



Jan.-l9,1937.v l J, 'B QHLSON 2,067,981

CROS S -OVER SWITCH Filed Nov. 2, 1955 2 Sheets-Sheet l Tg3. 'am

Jan. 19, 1937. J, B, OHLSON 2,067,981

cRoss-oyER `SWITCH Filed Nov. 2, 19:55 2 sheets-sheet 2 1&4.

k Y j t. f ze Q5 (ze o ci II *i www Patented Jan.' 19, -`1937 (moss-oven swrrcn John n.. ohisommkaway, N. Y.. mmm to Ira, Milton Jones, Milwauk ee, Wil.

Application November #1.933, Serial No. 696,327

3 Claims. (Cl. 10496) This invention relates to overhead conveyer tracks and refers more particularly to switches or cross-overs used therewith for switching the trolley wheels or rollers which travel along the tracks from one track to another.

One requirement for such cross-over switches found in leather stretchingand drying systems in which the overhead tracks support stretching frames for movement from a drying chamber to a toggling station and vice versa. Each stretching frame is supported from the overhead tracks by two rollers or trolley wheels, one travelling on onetrack and the other travelling on a second track.

To conserve space within the drying chamber and to keep the openings through which the stretching frames enter and leave the drying chamber as narrow as possible it is necessary that the frames move endwise or edgewise all the way into the chamber and then move flatwise along the length of the chamber into alignment with the exit opening to be endwise or edgewise movable therethrough. This movement of the stretching frames requires that the trolleys crossover from one track to the other. Heretofore, this has been accomplished by a pivotally mounted switch member actuated electromagnetically from one position to another. This construction was expensive, complicated and objectionable for many reasons and it is, therefore, an object of thisv invention to provide a simple inexpensive automatic switch or cross-over which is entirely mechanical to avoid the necessity for expensive and objectionable electrical equipment.

More speciilcally, it is an object of this invention to provide a cross-over switch for the purpose set forth which consists essentially of a movable member yieldably held in an inoperative position and movable'by the trolley wheels running on the tracks with which the cross-over is employed, to its operative position bridging the space from one track to another.

It is also an object of this invention to provide means for preventing derailment of the wheels running on the supporting tracks in the event of backward motion of the wheels. i

A further object of this invention is to provide simple means for releasably locking the switch member in its operative position to permit backward motion of theI trolley wheels across the switch, when desired. l

With the above and other objects in view which will appear as the description proceeds, my invention resides in the novel construction, combination and arrangement of parts substantially as hereinafter described and more particularly defined by the appended claims, it being understood that such changes in the precise embodiment of the herein disclosed invention may be made as come within the scope of the claims.

In the accompanying drawings, I have illustrated one complete example of the physical embodiment of my invention constructed according to the best mode I have so far devised for the practical application of the principles thereof, and in which:

Figure 1 is a top view of a switch or cross-over embodying this invention;

Figure 2 is a section view taken through Figure 1 on the plane of the line 2-2 and showing the cross-over substantially in side elevation Figure 3 is a `detail section view taken cn the plane of the line 3-3 of Figure l, to show the manually operable latch for securing the switch member in its operative bridging position;

Figure 4 is a diagrammatic plan view of a leather stretching and drying system incorporating the cross over or switch of this invention; and

Figure 5 is a diagrammatic end view of the structure shown in Figure 4.

Referringnow more particularly to the accompanying drawings in which like numerals indicate like parts throughout the several views, the numerals 5 and 8 designate two overhead supporting rails or tracks, which, for convenience, may be referred to as inner and outer tracks, respectively. The tracks may have any desired cross sectional shape, but in the present instance, are shown as I beams, the upper flanges 'of which are attached to suitable supporting means (not shown) and the lower anges of which provide the actual tracks on which trolley wheels 1 run.

As is customary, in conveyer structures in which overhead tracks are employed, the trolley wheels are arranged in pairs, one at each side of the track, and are connected through a swivel connection 8 with the device to be movable along the tracks.

At the point Where a cross-over from the inner to the outer track and vice versa, is necessary, the tracks are cutaway and their ends are rigidly connected by a frame 9 of angle iron cross pieces I0. 'I'he frame 9' may be suitably supported from the ceiling or other overhead structure in any desired manner to provide a rigid support for the tracks at this point.

One end portion of each track is curved inwardly asjat Il with the extremity thereof terminating in `straight-line alignment, with a curved acarrier bracket l2 supported from the frame 9 adjacent the opposite end of the other track to form a continuation thereof. The

'brackets I2 have laterally projecting anges I3,

which form continuations of the lower ilanges of the I beam tracks to provide the support for the wheels At their outer extremities, the brackets are provided with spaced ears I4 between which bridging members I5 are hingedly mounted as at I6. The tops ol the bridging members I5 are shaped like the lower Iianges of the I beams so that upon being lowered to operative bridging positions, they form substantially continuations'` of the tracks propel'. v

When in their operative positions, the bridging members span the distance between the extremities of the brackets and the diagonally opposite ends of the tracks as clearly shown in Figure 1, and to support the free ends of the bridging members, the curved track ends have ledges I1 on which the bridging member ends rest.

The bridging members are normally held 1n raised inoperative positions by torsion springs I8, coiled about the hinge pins I6, with their opposite ends engaging the bridging members and the brackets. It is thus possible to lower either bridging member to its operative position with* out `interference from the other bridging member.

Lowering of the bridging members to their operative positions is effected by the engagement of the rollers or trolley wheels 'I with the bridging members, as the wheels move outwardly along the ilangcs of the brackets I2, so that a set of wheels travelling outwardly along either track, automatically moves its own switch member or cross-over into position to carry such set of wheels to the other track.

The springs I8, of course, return the bridging members to their raised inoperative positions immediately after the passage of the wheels thereover.

To preclude backing the wheels off of the ends f of the curved track extensions II, an automatic blocking member I9 is provided for each open track end. This blocking member consists of a bell crank lever pivotally mounted on the web of the track as at 20, with the long arm 2| thereof hanging downwardly by gravity and the short arm 22 directed toward the end of the track and arranged to engage the underside of the top flange of the track. Consequently, it is possible to swing the bell crank lever in a clockwise direction with respect to Figure 2, but impossible to move the same in a counterclockwise direction beyond its normal operative position.

As a wheel leaves the bridging member and rides onto the curved track extension I I, it abuts the long arm 2| of the blocking member and swings the same about its pivot. To insure engagement of the arm 2| with the wheel, the arm is offset as at 23, to be spaced from the web of the track. The short arm 22, however, lies closely adjacent the web so that as the lever swings in response to the passage of the wheel, the short arm will notl interfere with its passage. After the wheel passes the blocking lever, it swings back by gravity to its normal operative position and provides an effective barrier to prevent backing the wheel oi the track.

If, for any reason, it is desired to back the wheel across the bridging member, the bridging member may be held down in its operative position by engaging a pivotal catch 24 carried there-y by with the ledge |1, as illustrated in dotted lines in Figure 3. It is, of course, necessary to hold the blocking member I9 in its inoperative position to permit the backward motion of the wheel therepast.

The switch or cross-over structure described is readily applicable to many different installations, but for the purpose of illustrating a complete and practical application of the invention, it is shown in Figures 4 and 5, in conjunction with a leather stretching and drying system. The inner and outer tracks 5 and 6 in this system form supports for a plurality of stretching and drying frames indicated generally by the numeral 25, and provide means for conveniently conveying the frames to and from a drying chamber 26.

The tracks are arranged in loops one within the other, with their stretches in the drying chamber spaced apart considerably so that the frames hung therefrom are positioned substantially at right angles to the tracks allowing the frames to hang in close side-by-side relationship.

At one end of the drying chamber, the tracks converge and pass out through an exit- 2'I leading from the drying chamber, to continue in close parallel relationship for a distance outwardly of the drying chamber outer wall to a toggling station, and then back into the drying chamber, through an entrance 28 in its outer wall.

As will be apparent from Figure 4 the frames while in the drying chamber are movable fiatwise between positions of alignment with the entrance and exit openings and move edgewise into and out of the chamber. Unless this scheme of moving the frames is employed the openings will have to be considerably wider and much space would have to be wasted inside of the chamber to accommodate the swinging of the frames which any other arrangement would entail.

The cross-over which is located above the toggling station makes possible the desirable motion or travel of the frames. Through it the forward supporting trolleys of the frames are switched from the inner track to the outer track as the frames are brought into toggling position and the trailing trolleys of the frames are switched from the outer track to the inner tr-ack as the frames are moved from the toggling position back into the drying chamber.

The drying and stretching frames may be of conventional construction comprising a sheet of perforated metal 29 supported in a frame 30, which is hung from a bail 3|. The bail 3| has the swivel connections 8, which carry the wheels 1 attached thereto.

From the foregoing description taken in connection with the accompanying drawings, it will be readily apparent to those skilled in the art, that this invention provides a simple inexpensive switch or cross-over for overhead rails or tracks.

What I claim as my invention is:

1. In combination with a pair of overhead supporting tracks of a leather stretching and drying system which tracks have side-by-side parallel portions with adjacent breaks therein and with the end portions of the tracks at said breaks directed inwardly so that the end portions of one track are in line with the diagonally opposite end portions of the other track and said system including stretching frames and trolleys to movably and pivotally support the frames from the tracks, there being two trolleys for each frame with one trolley riding on each etrack, means for automatically switching the trolleys from one track to the other and vice versa as the stretching frames are moved along said parallel portions of the tracks comprising, hinged bridging members normally in inoperative positions disposed in the path oiadvancingtrolleys and movable-to operative positions bridging the spaces between the diagonally opposite and aligned end portions oi the supporting tracks.

2. In combination with overhead supporting tracks of a leather stretching and drying system including stretching frames each having two trolleys to movably and pivotally support the same from the tracks, said tracks being in the form of two loops, one-within the other with two parallel stretches, one spaced widely and the other closely adjacent, the trolleys of each frame rlmning one on each track, and said trolleys being spaced apart a distance substantially equal to the distance between the parallel track sections at their widest spacing so that the frames supported therefrom hang in planes substantially at right angles to said portions o! the tracks, and said closely adjacent'parallel portions of the tracks having adjacent breaks therein, means at said breaks for A switching the trolleys from one track to the other so as to reverse the position of the frames as they are moved along the tracks onto and off of the widely spaced parallel portions thereof, said switching means comprising bridging members to span the distances from one end oi' each track to the other end of theother track, and means yieldingly holding the bridging members in operative positions from which they are automatically 'movable to bridging positions by thel wheels of a advancing trolley.

3. In combination with the overhead conveyer tracks of a leather stretching and drying system including stretching trames and trolleys to movably and pivotally support theframes from the tracks and a drying chamber into which the tracks extend to carry the stretching frames into and from said drying chamber, each frame having one trolley engaged with each track, said tracks having closely adjacent side by side substantially parallel portions outside the drying chamber which portions have adjacent breaks resulting in four open ends, means at said breaks for switching a trolley from one track to the other comp'rising bridging members to extend diagonally from one endof each track to the other end of the other track, and means to yieldingly hold the bridging members in'inoperative positions from JOHN B. OHLSON. 

